On the International Code of Area Nomenclature (ICAN): a reply to Zaragüeta-Bagils et al.


  • Lynne R. Parenti,

    Corresponding author
    1. Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution PO Box 37012 MRC 159 Washington, DC 20013-7012, USA
      *E-mail: parentil@si.edu
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  • ÁNgel L. Viloria,

    1. Centro de Ecología, Instituto Venezolano de Investigaciones Científicas, Apartado Postal 20632, Caracas 1020-A, Venezuela
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  • Malte C. Ebach,

    1. International Institute for Species Exploration and School of Life Sciences, College of Liberal Arts and Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85287-4501, USA
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  • Juan J. Morrone

    1. Museo de Zoología ‘Alfonso L. Herrera’, Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), 04510 Mexico DF, Mexico
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*E-mail: parentil@si.edu


In 2007 the Systematic and Evolutionary Biogeographical Association (SEBA) wrote and ratified the first draft of the International Code of Area Nomenclature (ICAN), which was posted subsequently on the SEBA website. The ICAN was published, along with an explanatory discussion, by Ebach et al. (Journal of Biogeography, 35, 2008, 1153–1157), an article that is the subject of criticism by Zaragüeta-Bagils et al. (Journal of Biogeography, 36, 2009, 1617–1618). We welcome discussion of the issues raised by these authors and respond to them briefly here. For many reasons, we reject the proposition that implementation of the ICAN be postponed until it is flawless. The ICAN has already been implemented. Further, it is the nature of nomenclatural codes to be proposed and then revised periodically to suit our applications. Most importantly, standardization of area names in biogeography is long overdue.

The first draft of the International Code of Area Nomenclature (ICAN) was written and ratified by members of the Systematic and Evolutionary Biogeographical Association (SEBA) and posted on its website (Ebach et al., 2007). An explanatory discussion and the text of the ICAN were published subsequently as a Guest Editorial in the Journal of Biogeography (Ebach et al., 2008). That editorial was the subject of a critique by Zaragüeta-Bagils et al. (2009) to which we reply briefly here. We are grateful for the attention paid by these authors to the ICAN, particularly by their comment that it ‘…constitutes a key step toward maturity of [biogeography]’. We offer some comments in anticipation of the benefits of public debate. Our subject headings mirror those in Zaragüeta-Bagils et al.’s (2009) critique.

Classification versus nomenclature

The explanatory discussion and the ICAN in Ebach et al. (2008) are explicit about the relationship between classification and nomenclature: the ICAN is concerned with nomenclature, not with particular methods to construct biogeographical classifications. That we mentioned the nomenclatural rules and classification of Linnaeus in the same sentence of the explanatory discussion does not mean that we equate or confuse these concepts (Zaragüeta-Bagils et al., 2009). This is one example of how Zaragüeta-Bagils et al. (2009) unfortunately conflate the explanatory discussion accompanying the ICAN and the ICAN itself. Similarly, they state that the ‘ICAN stipulates’ (Zaragüeta-Bagils et al., 2009) that taxonomic nomenclature is ruled by three codes. The three nomenclatural codes for natural living organisms – not those cultivated or viral – are noted in the explanatory discussion, not the ICAN.

Zaragüeta-Bagils et al.’s (2009) rejection of the ICAN statement that ‘[a]rea names may be grouped under more inclusive area names in order to represent a biogeographical taxonomic hierarchy’ using the argument that a hierarchy applies to areas, not names, is beside the point. A hierarchy of areas may be represented by words, by a complex map, or, ideally, both.


We agree that the use of classificatory ranks is arbitrary and gave several examples in our explanatory discussion of how in practice these may be applied or even ignored. The ICAN is criticized because ‘…the type-locality of a higher-rank area can be different from those of included areas’, and therefore, in the opinion of Zaragüeta-Bagils et al. (2009), it is impossible to make decisions on synonymy/homonymy. Few fields lack standards in the way that biogeography lacks standards to name areas. Because there have been no standards for naming biogeographical areas, in practice there are no type-localities for large, high-rank areas, such as the Neotropical region or the Austral realm. We explain how type-localities matter below.

In their application of the ICAN to areas occupied by Argentinean freshwater fishes, López et al. (2008) presented the following ranked area classification:

  •  Kingdom Austral (Kuschel, 1969)

    •   Region Andean (Shannon, 1927)
      •    Province Andean Cuyan
      •    Province Patagonian
  •  Kingdom Holotropical (Rapoport, 1968)
    •   Region Neotropical (Sclater, 1858)
      •    Province Aymaran
      •    Province Great Rivers
      •    Province Pampean

In so doing, they rejected Sclater’s (1858) broad Neotropical region which subsumed the Andean, and following Morrone (2006) favoured a more restricted concept of the Neotropical region. Had a locality within Patagonia been designated the type-locality for the Neotropical region sensu Sclater, it is likely that a different area classification would have been proposed by López et al. (2008) because the name ‘Neotropical’ would also be linked to Patagonia. We anticipate that with implementation of the ICAN, such potential nomenclatural conundrums will be addressed with the same tools available to users of biological nomenclature: discussion, debate, petitions, lists of rejected names and so on.

Ranks and names of ranks have been applied inconsistently to biogeographical areas. The statement in the ICAN that ‘[a] rank can only have one valid name’ (Sec. C, Art. 2.7) is not meaningless, as Zaragüeta-Bagils et al. (2009) claim. The statement means that for any given rank in an area classification there should be only one name. In the above example of a ranked area classification by López et al. (2008), the name of the Andean region (Shannon, 1927) has precedence over the names Neantarctic region (Monrós, 1958) or Andean Patagonian region (Ringuelet, 1961) (see Morrone, 2001).

Area definition

Biogeographical areas are tied to the endemic taxa that live in them. Article 1.1 of the ICAN states: ‘The objective of ICAN is to provide a universal naming system or nomenclature for areas of endemism used in biogeography and elsewhere’ (Ebach et al., 2008, p. 1156). An area would not be named or recognized if it had no biogeographical significance.

Zaragüeta-Bagils et al. (2009) bemoan the neglect of temporal data in the ICAN. Of course, a time period may be added to any area diagnosis/definition. The relationship between time and areas is abstract: specifying a temporal interval for a biogeographical area may be possible in some cases, not others. Temporal distribution data will enhance our understanding of biological distribution.

Diagnosis versus description

Diagnosis and description are treated as separate concepts in the ICAN. It would be apparent when a diagnosis and description are identical. Nevertheless, we see a benefit in Zaragüeta-Bagils et al.’s (2009) suggestion that an explicit diagnosis and description accompany the naming of an area of endemism.


The ICAN needs a more explicit statement on date of publication, especially as we anticipate electronic publication of many, if not most, proposals for names of areas. Examples of the distinction between ‘available’ and ‘valid’ where we have implicitly followed zoological rules as they apply to names of areas would also clarify our use of those terms.


Changes to ICAN that we describe above can be made through amendments or revision of the entire code. Most important, they should be public and readily available to all interested biogeographers. The ICAN specifies that amendments be published in Biogeografía, the online publication of the Systematic and Evolutionary Biogeographical Association.

Implementation and conclusion

We reject Zaragüeta-Bagils et al.’s (2009) proposal to shelve the ICAN until it is flawless. The ICAN has already been implemented (see López et al., 2008, above). Further, it is the nature of nomenclatural codes to be proposed and then revised periodically or amended as the need arises.

Standardization of area names in biogeography is long overdue. With sleek and sophisticated technologies, such as GPS and GIS, comes the expectation that biogeographical databases are robust and foolproof. If only that were true. A disquieting number of papers have recently exposed the long-term detrimental effects of having loose or no standards in documenting the occurrence of rare species (McKelvey et al., 2008), applying taxonomy in ecology (Bortolus, 2008) or building biogeographical databases (Robertson, 2008). Pushing aside standards will encourage vague and idiosyncratic biogeographical analyses that have little generality, comparability, repeatability or testability. Encouraging standards will have the opposite, more positive, effect.

Editor: David Bellwood